jquery在加载完iframe的内容后才进行下一步操作

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var iframe = document.getElementById("previewFrame");if (iframe.attachEvent) {iframe.attachEvent("onload", function() {                //以下操作必须在iframe加载完后才可进行$("#themes").find(".selected").trigger("click");});} else {iframe.onload = function() {                //以下操作必须在iframe加载完后才可进行$("#themes").find(".selected").trigger("click");};}
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